CN101502295B - Lactalbumin membrane as well as preparation method and application thereof - Google Patents

Abstract

The present invention discloses a calcium-containing lactalbumin membrane, a preparing method and the application thereof. The method provided by the invention for preparing the calcium-containing lactalbumin membrane comprises the following steps: 1) after executing degeneration treatment to the solution of calcium-containing lactalbumin membrane, mixing with the water-soluble calcium salt solution, spray drying for obtaining the calcium-containing particles; 2) after executing degeneration treatment to the calcium-containing lactalbumin membrane, mixing with the solution of calcium-containing particles and elasticizer, obtaining the calcium-containing lactalbumin membrane after membrane forming. The invention adopts a method of calcium coagulation. The calcium content of obtained membrane product can exceed the high-limit collection concentration when the calcium ions are directly added into the membrane. Furthermore the remarkable change of original physical-chemical property of membrane does not exist. The invention not only provides a novel way for the integrated development and use of whey liquid, but also enriches the kind of food, and provides a new way for the absorption of mineral matter for human body.

Description

Translated fromChinese

乳清蛋白膜及其制备方法与应用Whey protein film and its preparation method and application

技术领域technical field

本发明涉及功能乳品及食品包装领域，特别是涉及一种乳清蛋白膜及其制备方法与应用。The invention relates to the field of functional dairy products and food packaging, in particular to a whey protein film and its preparation method and application.

背景技术Background technique

传统塑料包装材料虽然价格低廉，加工方便，但因无法被微生物降解、使用后只能当废弃物抛弃，破坏了生态环境，影响到人类健康。随科技的发展及人类生活水平的提高，特别是近年来环保意识的不断增强，塑料包装废弃物对环境的危害越来越引起人们的重视，各国都在努力寻找符合可持续发展原则的“绿色包装”材料替代产品，相关安全、可降解包装材料的研究进展已有很多报道，其中可食用膜产品以其安全、无毒、环保、可食用且兼具营养性和风味性等特点而备受关注，成为当代食品工业科技发展的主要项目之一。Although traditional plastic packaging materials are cheap and easy to process, they cannot be degraded by microorganisms and can only be discarded as waste after use, which destroys the ecological environment and affects human health. With the development of science and technology and the improvement of human living standards, especially the increasing awareness of environmental protection in recent years, the harm of plastic packaging waste to the environment has attracted more and more attention. There have been many reports on the research progress of relevant safe and degradable packaging materials, among which the edible film products are highly regarded for their safety, non-toxicity, environmental protection, edible, nutritious and flavor characteristics. Attention has become one of the main projects in the development of science and technology in the contemporary food industry.

可食用膜是一类以可食性物质(蛋白质、多糖和脂肪等)为原料，通过分子间相互作用所形成的具有多孔网络结构的薄膜。它容易被生物降解，无环境污染；具有阻隔性能，可防止食品组分间因水分和其它物质的迁移而导致的食品变质；可作为食品风味剂、甜味剂、营养强化剂、抗氧化剂、抗微生物制剂等的载体。已公开的可食用包装膜主要是以蛋白质、脂肪、多糖类或其混合物等可以食用的原料为基础加工制成的。例如，CN 174039C涉及一种以马铃薯淀粉为主要原料、添加增稠剂和增塑剂后制作得到的复合食品包装膜；CN 1452916A介绍了一种含有天然植物提取物的可食用膜的制备方法；CN 1499926A介绍了一种以无支链淀粉为主要成膜剂、复配填充剂和增塑剂形成的可食用膜。Edible film is a kind of film with a porous network structure formed by intermolecular interactions using edible substances (proteins, polysaccharides, fats, etc.) as raw materials. It is easily biodegradable and has no environmental pollution; it has barrier properties and can prevent food deterioration caused by the migration of moisture and other substances between food components; it can be used as food flavoring agents, sweeteners, nutritional enhancers, antioxidants, Carriers for antimicrobial agents, etc. The disclosed edible packaging films are mainly processed on the basis of edible raw materials such as protein, fat, polysaccharides or mixtures thereof. For example, CN 174039C relates to a kind of composite food packaging film which takes potato starch as main raw material and adds thickener and plasticizer; CN 1452916A introduces a kind of preparation method of edible film containing natural plant extract; CN 1499926A has introduced a kind of edible film that takes non-pullulan as main film-forming agent, composite filler and plasticizer.

乳清液是以牛奶为原料生产干酪过程的废弃副产品之一。通常情况下，每生产1吨干酪，就约有10吨乳清废液产生。乳清蛋白是牛奶乳清中存在的一类重要蛋白质，具有很高的营养价值和生物学效价。乳清蛋白可食用包装材料是一种无废弃物的资源型包装材料，可使资源得到最大限度的利用，符合当代可持续发展原则和建设环境友好型社会的要求。Whey is one of the waste by-products of the cheese production process from milk. Normally, for every ton of cheese produced, about 10 tons of whey waste liquid is produced. Whey protein is an important protein in milk whey, which has high nutritional value and biological value. Whey protein edible packaging material is a waste-free resource-based packaging material, which can maximize the use of resources and meet the contemporary principles of sustainable development and the requirements of building an environment-friendly society.

近年来，以乳清蛋白为基料的可食用膜因具有良好的营养特性及成膜能力，所形成的薄膜透明、柔软、有弹性、不溶于水，在一定的湿度下具有优良的氧气、芳香物质和油脂的阻隔性，成为研究的热点。In recent years, the edible film based on whey protein has good nutritional characteristics and film-forming ability. The film formed is transparent, soft, elastic, insoluble in water, and has excellent oxygen, The barrier properties of aromatic substances and oils have become a research hotspot.

可食用包装膜材料除应具有作为包装材料的基本性能外，因其可食用特点，在满足安全性和可降解性的前提下，也应充分考虑其营养功能，开发相关的多功能价值。钙是目前人们需要强化补充的矿物质元素之一，在食品中合理控制增加钙的含量，为现代食品行业所关注，但在目前公开的技术中，尚未见到有关在膜体系中强化此类矿物质营养成分的方法的报道。Edible packaging film materials should not only have the basic performance as packaging materials, but also should fully consider their nutritional functions and develop related multifunctional values under the premise of satisfying safety and degradability due to their edible characteristics. Calcium is one of the mineral elements that people need to fortify and supplement at present. Reasonably controlling and increasing the content of calcium in food has attracted the attention of the modern food industry. Reports on methods for mineral nutrient composition.

发明内容Contents of the invention

本发明的目的是提供一种含钙乳清蛋白膜及其制备方法与应用。The purpose of the present invention is to provide a calcium-containing whey protein film and its preparation method and application.

本发明提供的制备含钙乳清蛋白膜的方法，包括如下步骤：The method for preparing calcium-containing whey protein film provided by the invention comprises the following steps:

1)将乳清分离蛋白溶液变性处理后，与水溶性钙盐溶液混合，喷雾干燥得到含钙粒子；1) Denaturing the whey protein isolate solution, mixing it with a water-soluble calcium salt solution, and spray-drying to obtain calcium-containing particles;

2)将乳清分离蛋白溶液变性处理后，与所述含钙粒子的水溶液及增塑剂混合，成膜后得到所述含钙乳清蛋白膜。2) After denaturing the whey protein isolate solution, it is mixed with the aqueous solution of the calcium-containing particles and a plasticizer to form a film to obtain the calcium-containing whey protein film.

该方法的步骤1)中，乳清分离蛋白溶液的质量百分比浓度为8-12％，优选10％；所述水溶性钙盐溶液的质量百分比浓度为0-12％，但不包括0，优选1-11.5％，更优选11.1％。In step 1) of the method, the mass percent concentration of the whey protein isolate solution is 8-12%, preferably 10%; the mass percent concentration of the water-soluble calcium salt solution is 0-12%, but excluding 0, preferably 1-11.5%, more preferably 11.1%.

在上述乳清分离蛋白溶液变性处理后，先调节pH值至3后，再与水溶性钙盐溶液混合。After the whey protein isolate solution is denatured, the pH value is first adjusted to 3, and then mixed with the water-soluble calcium salt solution.

另外，喷雾干燥步骤中，进风温度为170-190℃，优选180℃；出风温度为85-95℃，优选90℃；进样量为8-12ml/min，优选10ml/min。In addition, in the spray drying step, the inlet air temperature is 170-190°C, preferably 180°C; the outlet air temperature is 85-95°C, preferably 90°C; the injection volume is 8-12ml/min, preferably 10ml/min.

步骤2)中，含钙粒子水溶液的质量百分比浓度为小于等于1.8％，优选1.8％；所述增塑剂与所述乳清分离蛋白质量比为1∶1.5-1∶2.5，优选1∶2。该乳清分离蛋白溶液在变性处理前，先调节pH值至8。所用增塑剂为甘油。In step 2), the mass percent concentration of the aqueous solution containing calcium particles is less than or equal to 1.8%, preferably 1.8%; the mass ratio of the plasticizer to the whey protein isolate is 1:1.5-1:2.5, preferably 1:2 . The whey protein isolate solution is adjusted to pH 8 before denaturing. The plasticizer used is glycerin.

上述步骤1)和步骤2)中，乳清分离蛋白溶液的变性处理是在75-85℃处理30-40分钟，如可在80℃保持30分钟，即完成变性处理。In the above step 1) and step 2), the denaturation treatment of the whey protein isolate solution is performed at 75-85°C for 30-40 minutes, and if it can be kept at 80°C for 30 minutes, the denaturation treatment is completed.

按照上述方法制备得到的含钙乳清蛋白膜中，钙元素的质量百分含量为0-1.0％，但不包括0。In the calcium-containing whey protein film prepared by the above method, the mass percentage of calcium element is 0-1.0%, but 0% is not included.

上述含钙乳清蛋白膜及该蛋白膜在制备可食用包装膜材料中的应用，也属于本发明的保护范围。The calcium-containing whey protein film and the application of the protein film in the preparation of edible packaging film materials also belong to the protection scope of the present invention.

在制备乳清蛋白膜的过程中，如果直接向成膜液中加入超过极限聚集浓度(c.c.c)的钙离子，会由于双价正离子的静电屏蔽及桥联作用而导致体系内蛋白分子大量聚集，以至无法成膜。而本发明采用喷雾干燥的方法制备白色高钙聚集态颗粒，再将这些颗粒加入到膜液中，所得膜产品的钙含量可超过极限聚集浓度，且不会造成膜原有物化性质的显著变化。In the process of preparing whey protein film, if calcium ions exceeding the limit aggregation concentration (c.c.c) are directly added to the film-forming solution, a large amount of protein molecules in the system will be aggregated due to the electrostatic shielding and bridging effect of divalent positive ions , so that the film cannot be formed. However, the present invention adopts the method of spray drying to prepare white high-calcium aggregated particles, and then adds these particles into the membrane liquid, the calcium content of the obtained membrane product can exceed the limit aggregation concentration, and will not cause significant changes in the original physical and chemical properties of the membrane. .

本发明提供了一种在保持乳清蛋白膜原有物化性能基本不变的前提下，提高其钙含量的方法。该方法不仅提供了一条综合开发利用乳清液的新途径，且丰富了食品的种类，为人体矿物质的摄入提供了一条新途径。The invention provides a method for increasing the calcium content of the whey protein film under the premise of keeping the original physical and chemical properties of the whey protein film basically unchanged. The method not only provides a new way of comprehensively developing and utilizing the whey liquid, but also enriches the types of food, and provides a new way for the intake of human minerals.

附图说明Description of drawings

图1为本发明提供的制备含钙乳清蛋白膜的工艺路线。Fig. 1 is the technological route of preparing calcium-containing whey protein film provided by the present invention.

图2为纯乳清蛋白膜与含钙颗粒乳清蛋白膜透光率的比较图。Fig. 2 is a comparison chart of the light transmittance of a pure whey protein film and a whey protein film containing calcium particles.

图3为纯乳清蛋白膜与含钙颗粒乳清蛋白膜的实物图。Fig. 3 is a physical picture of a pure whey protein film and a whey protein film containing calcium particles.

具体实施方式Detailed ways

下面结合具体实施例对本发明作进一步说明，但本发明并不限于以下实施例。The present invention will be further described below in conjunction with specific examples, but the present invention is not limited to the following examples.

本发明提供的制备含钙乳清蛋白膜的方法，其具体工艺路线如图1所示。The method for preparing a calcium-containing whey protein film provided by the present invention has a specific process route as shown in FIG. 1 .

实施例1Example 1

按照下述步骤制备含钙乳清蛋白膜：Prepare calcium-containing whey protein films as follows:

1)用质量百分比浓度为10％的乳清分离蛋白(whey protein isolate，简称WPI)溶液，在80℃热变性处理30分钟，在pH值为3的条件下与质量百分比浓度为11.1％的CaCl₂溶液等质量(即Ca²⁺∶WPI＝2∶5)混合，以喷雾干燥方式得到白色含钙聚集态颗粒。其中，喷雾干燥的具体步骤为：1) Use a whey protein isolate (WPI) solution with a mass percentage concentration of 10%, heat denaturation treatment at 80° C. for 30 minutes, and mix it with 11.1% CaCl at a pH value of 3_{The two} solutions were mixed with equal masses (ie Ca²⁺ :WPI=2:5), and the white calcium-containing aggregated particles were obtained by spray drying. Wherein, the concrete steps of spray drying are:

所用喷雾干燥装置为现有常规装置；将该装置开机后，进入自动界面，按干燥工艺要求设置各个参数。参数设定后，点击自动按钮，程序自动控制该实验过程。本实验参数设定为：进风温度为180℃；出风温度为90℃；进样量为10ml/min。The spray drying device used is an existing conventional device; after starting the device, enter the automatic interface, and set various parameters according to the drying process requirements. After the parameters are set, click the Auto button, and the program will automatically control the experimental process. The parameters of this experiment are set as follows: the inlet air temperature is 180°C; the outlet air temperature is 90°C; the injection volume is 10ml/min.

该颗粒的粒径为3.1±0.1μm。EDTA滴定法测定该固体颗粒中钙的含量为17％。The particles had a particle diameter of 3.1±0.1 μm. The calcium content in the solid particles was determined to be 17% by EDTA titration.

2)配制质量百分比浓度为10％乳清分离蛋白溶液，调节溶液pH值为8，在80℃热变性处理30分钟后，加入步骤1)得到的含钙粒子的水溶液，该溶液的质量百分比浓度为1.80％，使体系内乳清分离蛋白的最终质量百分比浓度为8％，再加入增塑剂甘油(甘油∶WPI＝1∶2)，混匀后抽至真空度为0.1MPa进行脱气。取5mL该混合液于直径8cm的有机玻璃板上铺膜；在22℃、相对湿度56％的条件下放置48h，得到本发明提供的含钙乳清蛋白膜。2) Prepare a whey protein isolate solution with a mass percentage concentration of 10%, adjust the pH value of the solution to 8, and add the calcium particle-containing aqueous solution obtained in step 1) after heat denaturation treatment at 80° C. for 30 minutes. The mass percentage concentration of the solution is 1.80%, so that the final mass percent concentration of whey protein isolate in the system is 8%, then add plasticizer glycerin (glycerol: WPI = 1: 2), mix and pump to a vacuum of 0.1 MPa for degassing. Take 5mL of the mixed solution and lay a film on a plexiglass plate with a diameter of 8 cm; place it at 22° C. and a relative humidity of 56% for 48 hours to obtain the calcium-containing whey protein film provided by the present invention.

将上述含钙乳清蛋白膜按照下述测定及分析方法进行表征：The above-mentioned calcium-containing whey protein film is characterized according to the following measurement and analysis methods:

(1)固体膜中钙含量的测定(1) Determination of calcium content in solid film

参照美国官方分析化学师协会(Association of Official Analytical Chemists，AOAC)于1995年颁布的EDTA络合滴定法测定。使用直接加钙的方法(即向成膜液中直接加入钙离子)制得的乳清蛋白膜中的钙含量低于0.5％，而使用本发明所制备的蛋白膜中钙含量达1％，为前者的2倍。Refer to the EDTA complexometric titration method promulgated by the Association of Official Analytical Chemists (AOAC) in 1995. The calcium content in the whey protein film produced by the method of directly adding calcium (that is, directly adding calcium ions to the film-forming solution) is lower than 0.5%, while the calcium content in the protein film prepared by using the present invention reaches 1%. 2 times that of the former.

(2)膜厚度的测定方法(2) Measuring method of film thickness

用数显千分尺测量厚度。使用本发明所制备的蛋白膜的厚度为90-100μm，与纯乳清蛋白膜基本相同。Measure the thickness with a digital micrometer. The thickness of the protein film prepared by using the present invention is 90-100 μm, which is basically the same as that of the pure whey protein film.

(3)刺穿性能的测定方法(3) Determination method of piercing performance

使用TMS-Pro质构仪进行测定。刺穿强度(PS，N/mm)按式(1)计算：The determination was carried out using a TMS-Pro texture analyzer. The piercing strength (PS, N/mm) is calculated according to formula (1):

$\mathrm{<span><span>PS</span>P.S.</span>}<span><span>=</span>=</span>\frac{{\mathrm{<span><span>F</span>f</span>}}_{\mathrm{<span><span>p</span>p</span>}}}{\mathrm{<span><span>L</span>L</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>)</span>)</span>$

式(1)中：F_P-最大刺穿力(N)；L-膜样品的厚度(mm)。In the formula (1): F_P - the maximum piercing force (N); L - the thickness of the film sample (mm).

纯乳清蛋白膜的刺穿强度为28.1±2.3N/mm；使用本发明所制备的蛋白膜的刺穿强度为27.9±2.4N/mm。说明膜的刺穿性能没有显著变化。The puncture strength of the pure whey protein film is 28.1±2.3N/mm; the puncture strength of the protein film prepared by using the present invention is 27.9±2.4N/mm. It shows that the puncture performance of the membrane has not changed significantly.

(4)拉伸性能的测定方法(4) Determination of tensile properties

参照ASTM(1995)法，使用TMS-Pro质构仪测定拉伸性能，其中拉伸速度为1mm/s。拉伸强度(TS，N/mm²)按式(2)计算：Referring to the ASTM (1995) method, the tensile properties were measured using a TMS-Pro texture analyzer, wherein the tensile speed was 1mm/s. Tensile strength (TS, N/mm² ) is calculated according to formula (2):

$\mathrm{<span><span>TS</span>TS</span>}<span><span>=</span>=</span>\frac{{\mathrm{<span><span>F</span>f</span>}}_{\mathrm{<span><span>t</span>t</span>}}}{\mathrm{<span><span>L</span>L</span>}<span><span>\&times;</span>\&times;</span>\mathrm{<span><span>W</span>W</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>2</span>2</span>}<span><span>)</span>)</span>$

式(2)中，F_t——最大拉力(N)In formula (2), F_t ——Maximum pulling force (N)

L——膜样品的厚度(mm)L——thickness of film sample (mm)

W——膜样品的宽度(mm)。W——the width (mm) of the film sample.

纯乳清蛋白膜的拉伸强度为33.7±5.5N/mm²；使用本发明所制备的蛋白膜的拉伸强度为32.1±2.9N/mm²。说明膜的刺穿性能没有显著差异。The tensile strength of the pure whey protein film is 33.7±5.5N/mm² ; the tensile strength of the protein film prepared by using the present invention is 32.1±2.9N/mm² . It shows that there is no significant difference in the puncture performance of the membrane.

(5)水蒸汽透过系数(WVP)的测定方法(5) Determination method of water vapor transmission coefficient (WVP)

参照GB 1037-88法，采用拟杯子法，并加以适当调整后测定。水蒸气透过系数按式(3)计算：Refer to the GB 1037-88 method, adopt the quasi-cup method, and make appropriate adjustments for determination. The water vapor transmission coefficient is calculated according to formula (3):

$\mathrm{<span><span>WVP</span>WVP</span>}<span><span>(</span>(</span>\mathrm{<span><span>g</span>g</span>}<span><span>\&CenterDot;</span>\&Center\; Dot;</span>\mathrm{<span><span>mm</span>mm</span>}<span><span>/</span>/</span>{\mathrm{<span><span>m</span>m</span>}}^{\mathrm{<span><span>2</span>2</span>}}<span><span>\&CenterDot;</span>\&Center\; Dot;</span>\mathrm{<span><span>d</span>d</span>}<span><span>\&CenterDot;</span>\&Center\; Dot;</span>\mathrm{<span><span>KPa</span>KPa</span>}<span><span>)</span>)</span><span><span>=</span>=</span>\frac{\mathrm{<span><span>W</span>W</span>}<span><span>\&times;</span>\&times;</span>\mathrm{<span><span>x</span>x</span>}}{\mathrm{<span><span>A</span>A</span>}<span><span>\&times;</span>\&times;</span>\mathrm{<span><span>T</span>T</span>}<span><span>\&times;</span>\&times;</span>\mathrm{<span><span>\&Delta;P</span>\&Delta;P</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>3</span>3</span>}<span><span>)</span>)</span>$

式(3)中，In formula (3),

W——透湿杯的增重(g)W——Weight gain of moisture-permeable cup (g)

X——膜的厚度(mm)X——film thickness (mm)

A——膜外露面积(cm²)A——film exposed area (cm² )

T——测量间隔时间(h)T——measurement interval time (h)

ΔP——膜两侧的水蒸气压差(kPa)。ΔP—the water vapor pressure difference on both sides of the membrane (kPa).

纯乳清蛋白膜的水蒸气透过系数为21.0±0.9g·mm/24h·m²·kPa；使用本发明所制备的蛋白膜的水蒸气透过系数为20.1±1.0g·mm/24h·m²·kPa。说明膜的阻湿性能没有显著变化。The water vapor transmission coefficient of the pure whey protein film is 21.0±0.9g mm/24h m² kPa; the water vapor transmission coefficient of the protein film prepared by using the present invention is 20.1±1.0g mm/24h· m² kPa. It shows that the moisture barrier performance of the film has no significant change.

(6)透光率和透明度的测定(6) Determination of light transmittance and transparency

采用紫外-可见分光光度法测定膜在波长为200nm到800nm的吸光度值，所得透光率结果如图2所示，其中，曲线a为本发明提供的含钙乳清蛋白膜的透光率，曲线b为纯乳清蛋白膜的透光率。将膜在600nm时的吸光度值除以膜的厚度即为膜的透明度。按照该方法计算得到：纯乳清蛋白膜的透明度为0.783±0.062，本发明提供的含钙乳清蛋白膜的透明度为0.760±0.011。可知本发明提供的含钙乳清蛋白膜的透明度与纯乳清蛋白膜相比无显著变化。另外，纯乳清蛋白膜与含钙颗粒乳清蛋白膜的实物图分别如图3a和图3b所示。由图可知两种蛋白膜的外观性状无明显差别。The absorbance value of the film at a wavelength of 200nm to 800nm is measured by ultraviolet-visible spectrophotometry, and the obtained light transmittance result is as shown in Figure 2, wherein, curve a is the light transmittance of the calcium-containing whey protein film provided by the present invention, Curve b is the light transmittance of the pure whey protein film. Divide the absorbance value of the film at 600nm by the thickness of the film to get the transparency of the film. Calculated according to the method: the transparency of the pure whey protein film is 0.783±0.062, and the transparency of the calcium-containing whey protein film provided by the invention is 0.760±0.011. It can be seen that the transparency of the calcium-containing whey protein film provided by the present invention has no significant change compared with the pure whey protein film. In addition, the physical pictures of the pure whey protein film and the whey protein film containing calcium particles are shown in Figure 3a and Figure 3b, respectively. It can be seen from the figure that there is no significant difference in the appearance properties of the two protein films.

实施例2Example 2

按照下述步骤制备含钙乳清蛋白膜：Prepare calcium-containing whey protein films as follows:

1)用质量百分比浓度为10％的乳清分离蛋白(whey protein isolate，简称WPI)溶液，在85℃热变性处理25分钟，在pH值为3的条件下与质量百分比浓度为10％的CaCl₂溶液等质量(即Ca²⁺∶WPI＝2∶5)混合，以喷雾干燥方式得到白色含钙聚集态颗粒。其中，喷雾干燥的具体步骤为：1) Use a whey protein isolate (whey protein isolate, referred to as WPI) solution with a mass percentage concentration of 10%, heat denaturation treatment at 85° C. for 25 minutes, and mix it with 10% mass percentage concentration of CaCl under the condition of a pH value of 3_{The two} solutions were mixed with equal masses (ie Ca²⁺ :WPI=2:5), and the white calcium-containing aggregated particles were obtained by spray drying. Wherein, the concrete steps of spray drying are:

开机后，进入自动界面，按干燥工艺要求设置各个参数。参数设定后，点击自动按钮，程序自动控制该实验过程。本实验参数设定为：进风温度为190℃；出风温度为90℃；进样量为8ml/min。After starting up, enter the automatic interface, and set various parameters according to the drying process requirements. After the parameters are set, click the Auto button, and the program will automatically control the experimental process. The parameters of this experiment are set as follows: the inlet air temperature is 190°C; the outlet air temperature is 90°C; the injection volume is 8ml/min.

该颗粒的粒径为3.1±0.1μm。EDTA滴定法测定该固体颗粒中钙的含量为17％。The particles had a particle diameter of 3.1±0.1 μm. The calcium content in the solid particles was determined to be 17% by EDTA titration.

2)配制质量百分比浓度为10％乳清分离蛋白溶液，调节溶液pH值为8，在85℃热变性处理25分钟后，加入步骤1)得到的含钙粒子的水溶液，该溶液的质量百分比浓度为1.80％，使体系内乳清分离蛋白的最终质量百分比浓度为8％，再加入增塑剂甘油(甘油∶WPI＝1∶2)，混匀后抽至真空度为0.1MPa进行脱气。取5mL该混合液于直径8cm有机玻璃板上铺膜；在22℃、相对湿度56％的条件下放置48h，得到本发明提供的含钙乳清蛋白膜。2) Prepare a whey protein isolate solution with a mass percentage concentration of 10%, adjust the pH value of the solution to 8, heat denaturation treatment at 85°C for 25 minutes, add the aqueous solution containing calcium particles obtained in step 1), and the mass percentage concentration of the solution 1.80%, so that the final mass percent concentration of whey protein isolate in the system is 8%, then add plasticizer glycerin (glycerol: WPI = 1: 2), mix and pump to a vacuum of 0.1 MPa for degassing. Take 5mL of the mixed solution and lay a film on a plexiglass plate with a diameter of 8 cm; place it at 22° C. and a relative humidity of 56% for 48 hours to obtain the calcium-containing whey protein film provided by the present invention.

将上述含钙乳清蛋白膜按照下述测定及分析方法进行表征：The above-mentioned calcium-containing whey protein film is characterized according to the following measurement and analysis methods:

(1)固体膜中钙含量的测定(1) Determination of calcium content in solid film

参照美国官方分析化学师协会(Association of Official Analytical Chemists，AOAC)于1995年颁布的EDTA络合滴定法测定。使用直接加钙的方法(即向成膜液中直接加入钙离子)制得的乳清蛋白膜中的钙含量低于0.5％，而使用本发明所制备的蛋白膜中钙含量达1％，为前者的2倍。Refer to the EDTA complexometric titration method promulgated by the Association of Official Analytical Chemists (AOAC) in 1995. The calcium content in the whey protein film produced by the method of directly adding calcium (that is, directly adding calcium ions to the film-forming solution) is lower than 0.5%, while the calcium content in the protein film prepared by using the present invention reaches 1%. 2 times that of the former.

(2)膜厚度的测定方法(2) Measuring method of film thickness

用数显千分尺测量厚度。使用本发明所制备的蛋白膜的厚度为90-100μm，与纯乳清蛋白膜基本相同。Measure the thickness with a digital micrometer. The thickness of the protein film prepared by using the present invention is 90-100 μm, which is basically the same as that of the pure whey protein film.

(3)刺穿性能的测定方法(3) Determination method of piercing performance

使用TMS-Pro质构仪进行测定。刺穿强度(PS，N/mm)按式(1)计算：The determination was carried out using a TMS-Pro texture analyzer. The piercing strength (PS, N/mm) is calculated according to formula (1):

$\mathrm{<span><span>PS</span>P.S.</span>}<span><span>=</span>=</span>\frac{{\mathrm{<span><span>F</span>f</span>}}_{\mathrm{<span><span>p</span>p</span>}}}{\mathrm{<span><span>L</span>L</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>)</span>)</span>$

式(1)中：F_P-最大刺穿力(N)；L-膜样品的厚度(mm)。In the formula (1): F_P - the maximum piercing force (N); L - the thickness of the film sample (mm).

纯乳清蛋白膜的刺穿强度为28.1±2.3N/mm；使用本发明所制备的蛋白膜的刺穿强度为27.0±3.7N/mm。说明膜的刺穿性能没有显著变化。The puncture strength of the pure whey protein film is 28.1±2.3N/mm; the puncture strength of the protein film prepared by using the present invention is 27.0±3.7N/mm. It shows that the puncture performance of the membrane has not changed significantly.

(4)拉伸性能的测定方法(4) Determination of tensile properties

参照ASTM(1995)法，使用TMS-Pro质构仪测定拉伸性能，其中拉伸速度为1mm/s。拉伸强度(TS，N/mm²)按式(2)计算：Referring to the ASTM (1995) method, the tensile properties were measured using a TMS-Pro texture analyzer, wherein the tensile speed was 1mm/s. Tensile strength (TS, N/mm² ) is calculated according to formula (2):

$\mathrm{<span><span>TS</span>TS</span>}<span><span>=</span>=</span>\frac{{\mathrm{<span><span>F</span>f</span>}}_{\mathrm{<span><span>t</span>t</span>}}}{\mathrm{<span><span>L</span>L</span>}<span><span>\&times;</span>\&times;</span>\mathrm{<span><span>W</span>W</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>2</span>2</span>}<span><span>)</span>)</span>$

式(2)中，F_t——最大拉力(N)In formula (2), F_t ——Maximum pulling force (N)

L——膜样品的厚度(mm)L——thickness of film sample (mm)

W——膜样品的宽度(mm)。W——the width (mm) of the film sample.

纯乳清蛋白膜的拉伸强度为33.7±5.5N/mm²；使用本发明所制备的蛋白膜的拉伸强度为31.2±4.7N/mm²。说明膜的刺穿性能没有显著差异。The tensile strength of the pure whey protein film is 33.7±5.5N/mm² ; the tensile strength of the protein film prepared by using the present invention is 31.2±4.7N/mm² . It shows that there is no significant difference in the puncture performance of the membrane.

(5)水蒸汽透过系数(WVP)的测定方法(5) Determination method of water vapor transmission coefficient (WVP)

参照GB 1037-88法，采用拟杯子法，并加以适当调整后测定。水蒸气透过系数按式(3)计算：Refer to the GB 1037-88 method, adopt the quasi-cup method, and make appropriate adjustments for determination. The water vapor transmission coefficient is calculated according to formula (3):

$\mathrm{<span><span>WVP</span>WVP</span>}<span><span>(</span>(</span>\mathrm{<span><span>g</span>g</span>}<span><span>\&CenterDot;</span>\&CenterDot;</span>\mathrm{<span><span>mm</span>mm</span>}<span><span>/</span>/</span>{\mathrm{<span><span>m</span>m</span>}}^{\mathrm{<span><span>2</span>2</span>}}<span><span>\&CenterDot;</span>\&Center\; Dot;</span>\mathrm{<span><span>d</span>d</span>}<span><span>\&CenterDot;</span>\&Center\; Dot;</span>\mathrm{<span><span>KPa</span>KPa</span>}<span><span>)</span>)</span><span><span>=</span>=</span>\frac{\mathrm{<span><span>W</span>W</span>}<span><span>\&times;</span>\&times;</span>\mathrm{<span><span>x</span>x</span>}}{\mathrm{<span><span>A</span>A</span>}<span><span>\&times;</span>\&times;</span>\mathrm{<span><span>T</span>T</span>}<span><span>\&times;</span>\&times;</span>\mathrm{<span><span>\&Delta;P</span>\&Delta;P</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>3</span>3</span>}<span><span>)</span>)</span>$

式(3)中，In formula (3),

W——透湿杯的增重(g)W——Weight gain of moisture-permeable cup (g)

X——膜的厚度(mm)X——film thickness (mm)

A——膜外露面积(cm²)A——film exposed area (cm² )

T——测量间隔时间(h)T——measurement interval time (h)

ΔP——膜两侧的水蒸气压差(kPa)。ΔP—the water vapor pressure difference on both sides of the membrane (kPa).

纯乳清蛋白膜的水蒸气透过系数为21.0±0.9g·mm/24h·m²·kPa；使用本发明所制备的蛋白膜的水蒸气透过系数为19.2±1.3g·mm/24h·m²·kPa。说明膜的阻湿性能没有显著变化。The water vapor transmission coefficient of the pure whey protein film is 21.0±0.9g mm/24h m² kPa; the water vapor transmission coefficient of the protein film prepared by using the present invention is 19.2±1.3g mm/24h· m² kPa. It shows that the moisture barrier performance of the film has no significant change.

(6)透光率和透明度的测定(6) Determination of light transmittance and transparency

采用紫外-可见分光光度法测定膜在波长为200nm到800nm的吸光度值，所得透光率结果如图2所示，其中，曲线a为本发明提供的含钙乳清蛋白膜的透光率，曲线b为纯乳清蛋白膜的透光率。将膜在600nm时的吸光度值除以膜的厚度即为膜的透明度。按照该方法计算得到：纯乳清蛋白膜的透明度为0.783±0.062，本发明提供的含钙乳清蛋白膜的透明度为0.774±0.047。可知本发明提供的含钙乳清蛋白膜的透明度与纯乳清蛋白膜相比无显著变化。另外，该含钙颗粒乳清蛋白膜与纯乳清蛋白膜的外观性状无明显差别。The absorbance value of the film at a wavelength of 200nm to 800nm is measured by ultraviolet-visible spectrophotometry, and the obtained light transmittance result is as shown in Figure 2, wherein, curve a is the light transmittance of the calcium-containing whey protein film provided by the present invention, Curve b is the light transmittance of the pure whey protein film. Divide the absorbance value of the film at 600nm by the thickness of the film to get the transparency of the film. Calculated according to the method: the transparency of the pure whey protein film is 0.783±0.062, and the transparency of the calcium-containing whey protein film provided by the invention is 0.774±0.047. It can be seen that the transparency of the calcium-containing whey protein film provided by the present invention has no significant change compared with the pure whey protein film. In addition, there is no obvious difference in appearance properties between the whey protein film containing calcium particles and the pure whey protein film.

Claims (13)

1. a method for preparing the calcic lactalbumin membrane comprises the steps:

1) with after the whey isolate protein solution degenerative treatments, mix with the water-soluble calcium salting liquid, spray-drying obtains containing calcium particle;

The mass percent concentration of described whey isolate protein solution is 8-12%, and the mass percent concentration of described water-soluble calcium salting liquid is 0-12%, but does not comprise 0; The weight ratio of calcium ion and whey isolate protein is smaller or equal to 2: 5, but does not comprise 0;

2) with after the whey isolate protein solution degenerative treatments, mix with the described aqueous solution and the plasticizer that contains calcium particle, obtain described calcic lactalbumin membrane after the film forming;

The described mass percent concentration that contains the calcium particle aqueous solution is smaller or equal to 1.8%, but do not comprise 0; The mass ratio of described plasticizer and whey isolate protein is 1: 1.5-1: 2.5.

2. method according to claim 1 is characterized in that: in the described step 1), the mass percent concentration of described water-soluble calcium salting liquid is 1-11.5%; The weight ratio of calcium ion and whey isolate protein is 2: 5;

Described step 2) in, the mass ratio of described plasticizer and whey isolate protein is 1: 2.

3. method according to claim 2 is characterized in that: in the described step 1), the mass percent concentration of described water-soluble calcium salting liquid is 11.1%.

4. according to the arbitrary described method of claim 1-3, it is characterized in that: in the described step 1), in the spray-drying step, EAT is 170-190 ℃, and leaving air temp is 85-95 ℃, and sample size is 8-12ml/min.

5. method according to claim 4 is characterized in that: in the described step 1), in the spray-drying step, EAT is 180 ℃, and leaving air temp is 90 ℃, and sample size is 10ml/min.

6. method according to claim 1 is characterized in that: in the described step 1), after the described whey isolate protein solution degenerative treatments, after the adjusting pH value to 3, mix with the water-soluble calcium salting liquid more earlier.

7. method according to claim 1 is characterized in that: described step 2), described whey isolate protein solution is regulated pH value to 8 earlier before degenerative treatments.

8. method according to claim 1 is characterized in that: described degenerative treatments is that above-mentioned whey isolate protein solution was handled 30-40 minute at 75-90 ℃.

9. method according to claim 8 is characterized in that: described degenerative treatments is that above-mentioned whey isolate protein solution was handled 30 minutes at 80 ℃.

10. method according to claim 1 is characterized in that: described step 2), plasticizer is a glycerine.

11. the calcic lactalbumin membrane that the arbitrary described method for preparing the calcic lactalbumin membrane of claim 1-10 prepares.

12. calcic lactalbumin membrane according to claim 11 is characterized in that: in the described calcic lactalbumin membrane, the quality percentage composition of calcium constituent is 0-1.0%, but does not comprise 0.

13. claim 11 or the 12 described lactalbumin membranes application in preparation edible package membrane material.

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